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Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Analysis for Anti Tarnish Efficacy on Silver Plated Items
Q. May I ask, whoever knows, the procedure of anti-tarnish test using potassium sulfide?
Thanks,
Jessie
Zen Metal Coating & processing Corporation - Sto Tomas Batangas Philippines
September 26, 2019
⇩ Related postings, oldest first ⇩
2000
Q. Hello!
In our electroplating shop, we perform silver plating finished with an anti-tarnish protection. A quality control test employed to check the efficiency of the anti-tarnish protection involves the exposure of the silver plated items to an environment of hydrogen sulfide. The presence of black spots and burnings is taken as an indication that the anti -tarnish protection is not adequate.
Is this the correct test to be used? Are there standard methods referring to the analysis to be performed in association with electroplating and finishing solutions?
I would appreciate any help on this matter.
Thanks
Daniela from Malta
- Mriehel, Malta
Q. I am also interested in knowing a standard sterling silver anti tarnish test. I am also interested in methods of preventing sterling silver tarnish.
Cosmas KasekeJewelry manufacturing - Harare, Zimbabwe
2004
A. An article entitled "The Protection of Silver Against Atmospheric Attack" by Gay, Berçot and Pagetti, published in the May 2004 issue of Plating and Surface Finishing will tell you all the options for preventing tarnish.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004
Multiple threads merged: please forgive chronology errors :-)
Q. When I lived in N.Y. I developed a business making men's silver necklaces. They became popular enough so that I eventually sold perhaps 500 pieces. It required pouring silver into forms.
Until I moved to Florida there were no problems with them but now I can't stop them from tarnishing very quickly, perhaps two weeks, after a de-tarnishing treatment. I want to go back into the business as it satisfied my artistic hunger but I won't until I can resolve this problem.
I use Tarn-X tarnish remover
⇦this on
eBay or
Amazon [affil links]
to remove the tarnish. Question- can moving down south change my perspiration so dramatically as to cause the problem.- My neck seems to be a bit waxy since moving, could that be it? Is there an easy liquid et.al to proof the metal. I won't sell the necklaces until I can find an easy process for my customers to keep their precious jewelry beautiful.
crafts person - Ponte Vedra Bch., Florida
2004
My line of silver necklaces is tarnishing
A. Although I am no expert on jewelry (can't afford it!) I know this is a well known problem with silver jewelry. I suppose it is out of the question to ask fellow silver jewelry makers in Florida how they get over it? The reason for the problem is that perspiration and other skin secretions contain a mixture of fatty acids and lipids; I believe the mixtures ratio changes and RH as the temperature change. This is because the body tries to control its Trans Epidermal Water Loss (TEWL) by altering the composition of what it releases as it tries to reduce or prevent dehydration. These naturally occurring compounds contain sulfur, that will react with silver to tarnish it. Clearly Florida has a much better climate than New York, so there will be hotter temperatures but also higher humidities. There are numerous ways of overcoming it, including using nickel as an alloying agent, or using a chromate passivate. I would suggest you avoid both these as it will only cause you more problems with nickel allergies and falling foul of the environmentalists with hexavalent chromium. However, using sterling silver (92.5% Ag/7.5% Cu) may reduce the effect, but further reductions can be gained by using sterling silver and adding about 0.5% aluminum or chromium to it. You can also add a mixture of 0.9% zinc and 0.1% copper to the sterling silver. Also try asking the silver institute (www.silverinstitute.org)
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004
A. Hi Bob, you may want to consider casting your items using sterling silver marketed as "Deox" sterling from Hoover and Strong. The pieces will be more tarnish resistant. Also bear in mind you are residing in an area where salt air is part of the reason your silver is tarnishing quicker.
This factor combined human perspiration and skin colognes will accelerate oxidation of the silver. You may want to consider plating your silver items with a suitable thickness of bright rhodium to reduce customer complaints. Rhodium is excellent at resisting chemical attack. The downside is that it is about 70%-75% as bright as polished silver. The good news is that it will maintain that level of brightness and will be brighter than silver in the long term.
Good luck,
Metal Arts Specialties - Leonard, Michigan
2004
A. Are you using a silver polish after cleaning them? Try that and see if it works.
Simon Dupay- Roseville, Minnesota, USA
2004
A. SOME CAUSTIC IN A DISH AND KEEP IT IN STORAGE AREA. GOOD LUCK
Khair Shishani
aircraft maintenance - Al Ain, UAE
2004
A. I see you have mentioned Tarn-X tarnish remover
⇦this on
eBay or
Amazon [affil links]
when cleaning your silver. Tarn-X should be used only on items that have sat around for many years and have turned COMPLETELY BLACK and would takes weeks of rubbing to polish with a soft cloth. It is not like dust that just lands on it and can be rinsed away leaving the object as it was. The tarnish you see is the oxidization of the actual outermost layer of silver. Tarn-X is a strong mixture of chemicals that actually eats away the layer of tarnish, which is the top layer of silver! That is why Tarn-x leaves your silver with a whitish look to it that has to be polished off to make the silver have the mirror like finish it should have.
I have found that Silvo silver polish
⇦this on
eBay or
Amazon [affil links] , when allowed to dry, then wiped off with a soft cloth, or a baby hairbrush to get at the tiny places, leaves a beautiful finish on the silver and slows down the oxidization considerably.
- Quispamsis, NB, Canada
2004
Multiple threads merged: please forgive chronology errors :-)
Q. Hello everybody, where can I find the entire article: article entitled "The Protection of Silver Against Atmospheric Attack" by Gay, Berçot and Pagetti, published in the May 2004?
Please any advise will be very well accepted
Bye.
Silverstar - Italy
2005
A. Plating & Surface Finishing is the journal of the American Electroplaters and Surface Finishers Society (www.nasf.org). They can probably sell you a surplus copy of the May 2004 issue. If not, they can xerox the article and mail or fax it to you, presumably at nominal cost.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005
A. Hydrogen sulfide is the correct test.
A 2% solution is made and the articles are placed on top of a container on top of a wire gauze. Also place a comparison article alongside. The time difference between tarnishing of the two pieces will enable you to judge the efficiency of your anti-tarnish solution.
Take Care that you don't put a cover on the articles...The must lie openly on the wire gauze as oxygen/humidity is needed to complete the tarnishing reaction.
Deepak Whorra
silver craftwork - New Delhi, India
2007
Q. We are a gold jewelry manufacturer in Turkey.
Now we have started to produce jewelry in silver.
Please recommend us how we protect the brilliant surface against tarnish effect.
factory manager - Istanbul, Turkey
September 10, 2008
Q. Attn: Daniela Ciappara & Mr. Deepak
Dear Sir,
How to check the TARNISHING of SILVER COATING? The silver coating is not coated with any anti-tarnishing coat. Even in H2S test, how to co-relate the data? Hrs to years.
Regards,
READER - MUMBAI, MAJARASHTRA, India
December 12, 2008
A. We are manufacturing silver anti tarnish and the best method of testing the same would be definitely potassium or ammonium sulfide test. We have inferred that 2 minutes of withstanding in the sulfide test corresponds to at least 6 months of atmospheric tarnish prevention in atmosphere in real time, but the only varying factor is the sulfide content in atmosphere. The coastal areas are more prone to tarnish than the interiors due to the high sulfur ⇦this on eBay or Amazon [affil links] content in the atmosphere.
Mukund Shinde- Mumbai, Maharashtra, India
December 18, 2008
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